The invention relates to a camera of the automatic exposure control type, and more particularly, to such a camera with an automatic exposure control interlocked with an exposure meter and including a protective cover which is movable between a closed position where it covers a taking lens, a photometric assembly and the like and an open position where it permits them to be exposed.
A camera with an automatic exposure control which is interlocked with an exposure meter is already known in which a photovoltaic element such as a selenium photocell is used as a photometric element to receive reflected light from an object being photographed and wherein the output of the element is utilized to produce a deflection of the pointer of an ammeter and the deflection or the angular position of the pointer is in turn detected by a cam member in order to control an exposure process. A conventional camera of the type described is adapted to have a lens cap mounted on the distal end of a taking lens barrel in order to protect the taking lens and photometric assembly from external dust, fingerprints and rubbing.
The lens cap is selectively located such that it is mounted on the lens barrel in a manner to cover the taking lens and photometric assembly completely or it is removed from the lens barrel to permit to taking lens and photometric assembly to be exposed completely. Consequently, there has been no possibility that the lens cap assumes a half-open position where it partly covers the taking lens or photometric assembly to cause a vignetting of the image field or a partial exposure. Hence, in a conventional camera of the type described, there is no need to lock a shutter release or to disable an exposure controller, which would be required if the lens cap assumed a half-open position. Accordingly, the photocell is maintained in electrical connection with the ammeter.
Another camera of the automatic exposure control type is also known in which the shutter release is locked whenever the exposure is improper, by utilizing a reduced or increased deflection of the pointer of the ammeter. In such a camera, in order to prevent the shutter from being operated when the lens cap is mounted on the lens barrel, the photocell is positively maintained in electrical connection with the ammeter so that the shutter release can be locked whenever the lens cap is mounted.
However, when the lens cap in such a camera is replaced by a protective cover movable between a closed position where it covers the taking lens and the photometric assembly and an open position where it permits them to be exposed, the protective cover may assume a half-open position where it permits the taking lens and the photometric assembly to be exposed partly in the course of moving from the closed to the open position. Consequently, a vignetting of the imaging field or a partial exposure may be caused by a shutter release which may happen to be triggered in the half-open position of the protective cover.